Received: 20 February 2018
Accepted: 15 November 2018
First Online: 29 November 2018
Ethics approval and consent to participate
: This study was approved by Korea university medical center Guro hospital institutional review board (Human Research Protection Program Center; IRB No. 2018GR0020; IRB-approved on January 26, 2018). The study was performed in accordance with the Helsinki Declaration of 1983. The relevant ethics committee exempted this study from the requirement to obtain informed consent of patients after a waiver of informed consent was submitted with a detailed explanation.
: The authors have no competing interests that could potentially or inappropriately influence this study.
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